In a medium bowl, stir together flour, oats, soda and salt.
Stir dry ingredients into buttermilk/cereal mixture until well incorporated.
Place in large (5 qt.) ice cream pail or 5 qt. (4.3L) Tupperware. Store in refrigerator.
When ready to make muffins, preheat oven to 375 degrees.
Spray muffin tins (works better than the little paper liners because these tend to stick to the liners).
Stir batter and spoon into muffin tins only 2/3 full. Sprinkle with oats, if desired.
Bake at 375 degrees for 20 minutes – until toothpick comes clean.
Remove pan from oven and let rest 5 minutes, then remove muffins to cooling rack.